Means for automatically controlling centrifugal machines



May 13, 1939. R E 1,758,901

MEANS FOR AUTOMATICALLY CONTROLLING CENTRIFUGAL MACHINES Filed Dec. 8,1925 6 Sheets-Sheet 1 y 1930- E. ROBERTS 1,758,901

MEANS FOR AUTOMATICALLY CONTROLLING GENTRIFUGAL MACHINES Filed Dec. 8,1925 6 Sheets-Sheet 2 May 13, 1930. E. ROBERTS 1,758,991

MEANS FOR AUTOMATICALLY CONTROLLING CENTRIFUGAL MACHINES Fil'ed Dec. 8-,1925 6 Sheet s-Sheet s Ma 13, 1930 ROBE TS 1,758,901

MEANS FOR AUTOMATICALLY CONTROLLING CENTRiFUGAL MACHINES Filed Dec.8,1925 7 6 SheetsSheet 4 b Q J00 E v 0&- 3w

w a/ A35 '11111 111]] May 13; 1930. E. ROBERTS 1,758,901

' MEANS FOR AUTOMATICALLY CONTROLLING CENTRIFUGAL MACHINES Filed Dec. 8,1925 6 Sheets-Sheet 5 .qg mrwuw E. ROBERTS May 13, 1930.

MEANS FOR AUTOMATICALLY CONTROLLING CENTRIFUGAL MACHINES Filed Dec. 8,1925 6 Sheets-Sheet 6 Patented May 1 3," 193Q UNlTED STA Tss PATENT;OFFICE EUGENEROBERTS, or SALT LAKE CITY, UTAH} ASSIGNOR To THE WESTERNsTATEs MACHINE COMPANY, or sALT LAKE cITY, UTAH, A coaronATIoN or UTAHMEANS FOR AUTOMATICALLY CONTROLLING CENTRIEUGAL MACHINES "Applicationfiled December a, 1925. Serial No. 74,111.

, w p This invention relates to the-centrifugal purification of sugarand comprises a system ofautomatic control applied to a centrifugalmachine by which the successive cycle of op- 5 erations performed areaccurately and scientifically regulated to-suit the particularrequirements of difierent grades of sugarthat are received fbrtreatment, and thus avoid the loss and waste incident to the irregularand unreliable control heretofore maintained by the machine operatorCentrifugal purification of sugar or lik solids involves a cycle ofoperations as follows: first, the purging or centrifugal elimination offree syrup from the sugar grains; second, centrifugal washing to removethe coating of syrup that adheres to the sugar grains by means of a finespray directed against the revolving sugar mass walled up on the insideof the basket; third, the par tial drying of the wet sugar to the properstage to adapt it for the next operation of' granulating' After therequisite, degree of dryness is, ttained, the centrifugal is slowedpurified crystals upon an underneath conveyor, which carries it to theranulator. .Two operations may be advantageously performed by anattendant, namely, the loading of the sugar to the basket and, secondly,where a valved flat bottom basket is used,- instead of a conicalself-discharging basket, the discharging of the sugar through the hot- Itom when the machine has slowed down sufliciently to permit the useofdischarger plow. If the purging operation is contlnued too longbefore-spraying the adherent coating of syrup becomes hard, while if thespray be turned on before the free syrup is extracted, the residue ofthe free syrup impairs the efli: ciency of the washing operation. Ineither case an excessive amount of water would be required, but testshave shown that every pound of water sprayed upon the sugar'walldissolves about three pounds of sugar so that any excess of waterapplied involves. much waste of valuable material. It is also true thatif the drying operation, following the washing, be continued too longthe sugar begomes'so hard that it may smash the disdown, or s opped, topermit discharging the charger and cause a disastrous accident. If, onthe other hand, the sugar, when discharged, be not dry enough the excessmoisture will adversely afl'ect the granulating process. Differentbatches or grades of sugar require appropriate variationsin the durationof the different steps of the cycle.

'With the use of the automatic controlling apparatus, forming thepresent invention, the duration of every step in the cycle of operationsmay be exactly predetermined b a skilled overseer making the proper ajustinents'and may be varied 'to meet requirements for different gradesof sugar. The attendant, being merely required to loadand start themachine with no need of attention until the machine is automaticallyslowed down or stopped for. discharging, can readily care forsix oreight machines instead of-only two machines as heretofore, and produce amore uniform and better quality of product.

In general the invention consists in combining with the centrifugalmachine and its accompanying brake, and brake device, an automaticcontrol mechanism set in operation when the operator starts the machine,

tion of'tlle whole cycle of operations, include ing both the purging andthe washing of the sugar. g

1 In the accompanying drawings is illustrated a concrete embodiment ofthe principles of this invention,.in which: Figure 1 is a frontelevation showing the mechanism as applied to the driving, the braks ingand the washing mechanism of a centrifuand acting to determine preciselythe dura-' mechanism by which the automatic sprayer is set in operationand'by which the machine isstopped after the spraying operation isfinished.

Figure 5 is a plan view showing the mechanism for timing the machinecycle and starting the sprayer in action. 1

Figure 6 is an enlarged view showing, partly in section, the timingmechanismand the sprayer driving mechanism.

Figure 7 is a plan view of the sprayer.

Figure 8 is a front elevation of the sprayer, partly in section.. v

Figure 9 is a plan view of the brake mechanism.

Figure 10 is a front elevation of the brake mechanism.

In order to make clear the general nature of this invention I will firstexplain what is accomplished by the mechanism hereinafter explained.

The cycle of operations for purging and washing sugar or like materialin centrifugal machines will vary somewhat, according to the characterof the material being treated.- In general, however, in the purging andwashing of sugar the basket is spun or rotated at about 1100 RIP. M. fora period of perhaps a' little over one minute after the machine hasreached its maximum speed from the state of rest. After the material hasbeen suificiently pur ed by the centrifugal extraction of-the liquidsyrup, the operator then turns on the spray with the machine stillrunning in order to wash the grains or crystals and to free them fromthe adhering syrup. After a pre-.

--determined amount of purging andjwashing or spraying the machine isstopped and the sugar discharged to allow re-loading the machine. Thewhole cycle ordinarily consumes three minutes and requires both theattention and the judgment'of the workman who regulates theseoperations.-

With the use of the present improvements the workman merely throws thestarting lever or hand-Wheel, thereby operatively connecting the drivingmechanism with the centrifugal, and is then free to leave the machinesince, after a predetermined period, whose duration is determinedaccording to the adjustment or setting of the mechanism, the

sprayer is automatically started and is thereafter automaticallystopped, while after the spraying operation the machine itself isstopped by disconnecting the driving mechanism and setting the brake.

The invention is here shown as applied to a belt-driven centrifugalinwhich the belt runs from a loose pulley on the line shaft or drivingshaft 1, to the driving pulley a which, ac-

cording to established practice is secured -,to

thesuspension'shaft 6, around its center of suspension or'gyration whichshaft carries the usual centrifugal basket 0, which type of machine isillustrated in United States Letters Patent No. 1,627,868, granted to meMay clutch mechanism 3, which is thrown into clutching engagement withthe pulley by the lever 4, which is fulcrumed at 4:", above the lineshaft, and has an intermediate connectdirection to operate the clutchand release the brake and start the centrifugal timing mechanism. Thishorizontal shaft carries, at its rearend near to the vertical plane ofthe line-shaft, a pinion 5 which intermeshes with a sector arm 4* at thelower end of the shipper lever 4 so that the clockwise rotation of theshaft 9 and pinion 5 operates to establish driving connection throughthe clutch between the line-shaft and the driving pulley 2.

This shipper shaft 9 carries a torsion spring 6 so arranged as tonormally rotate the shaft in a counter-clockwise direction, that is, indirection to release the clutch and set the brake. To vary the tensionof the torsion spring I secure to the shaft 9 a bracket 9, in which ismounted a tangential screw or worm 9 which can be rotated by a wrench.This worm meshes with a worm-wheehG which is loose on the shaft and towhos hub is attached one end of the torsion spring 6. The other end ofthe torsion spring is anchored to a collar 6*, fast on the shaft. Byrotating the worm 9 in one direction or the other the tension of thetorsion spring may be increased or diminished, While the worm acts tomaintain the torsion-adjusting worm-wheel against rotation from itsadjusted position.

Near its forward end the shipper-shaft 9 carries another pinion 11 whichintermeshes with a sector arm 11 of a lever 11 whose upper end swings tothe left (Figure 1) when the shipper-shaft'is set by the operator. Theupper end of this lever is provided with a notch or recess to form ashoulder 11 for the reception of a pin 13, carried by the weight arm',13 of an angle-arm or lever 13, so that as the-weight 13 causes thisweight-arm to drop when the adjacent end of the lever 11 is swungoutwardly, the weight lever and its stop pin 13 serve to prevent thereturn of the shaft 9 to its initial position under the torque of thespring 6.

The short arm 13 of this bell-crank lever 13, is pivotally connectedwith a trip-rod 15, whose opposite end is connected with a threearmlever.16 arranged, in this case, on the opposite side of the centrifugalmachine.

The trip-lever 11 is fulcrumed at 12, andbelow its fulcral point isconnected with and attached to a connecting-rod or link whose oppositeend is attached to a brake-arm 51' which is securedto a rotatable brakeshaft 52, carrying, at its lower end, projecting pins 53 which areconnected by means of expanding toggles 54 with the free ends ofbrakeshoes 55 arranged interiorly of the pulley a,

which, is secured to the centrifugal shaft near its end of the beltpulley a. Further details against the interior of the brake from whichposition the brake shoes will be contracted to idle position, byrotation of the arm 51 and of the brake-spindle 52 in acounter-clockwise direction. It will therefore be seen that the rotationof the shipper-shaft 9 ma clockwise direction both couples the drivingpulley to the drive shaft and, at the same time, releases the brake fromengagement with the interior of the centrifugal machine pulle v Thethree-arm leyer 16, which is operatively, connectedwith theshipper-shaft in the manner described, operates both to start thecentrifugal timer, when the brake is re-' leased and the clutch is set,and also to trip the weight-arm and allow the torsiorpspring 6 to setthe brakeand release the clutch when the cycle of operations iscompleted.

The timer mechanism is closely associated with the automaticsprayer andis set in operation through the agency of the lever 17'. having a linkconnection 16*,with the lower 'end of the lever 16; The lower end of thelever 17 is provided with a clutch-fork 17 engaging a groove of a.sliding clutch. member or coupling member 18, which is itself splinedto'a horizontal shaft 20 on which is loosely mounted a sleeve 18",carrying, atone end, a clutch member18 and at its other end a worm-wheel18", intermeshing with a vertical worm 19, which is constantly rotatedwhile the centrifugal is running through the agency of intermeshing spurgears 19, 19 and vertical shaft 30, which is driven by means of beveledpinions 30 and a horizontal shaft 30 carried in a suitable housing 30,and having its'outer end driven by means of a;friction pulley 31pressing against the enlarged portion of,the spindle b of thece1rtrifugal. The friction pulley 31 has a worm driving connection withthe adjacent end of 20 which carries, at one end, a fixed collar .21serving as an anchorage for the end of a torsion spring 21.coiledaroundsaid shaft,

whose opposite end is anchored to a fixed part of the frame.

Near the outer end of said timer-shaft; outside of the housingor'bracket 20 which sup ports said shaft, is secureda dial plate or diskI 22 provided .with an inwardlyprojecting pin 22 adapted to abut againsta projecting fixed ledge or stop 20 of the housing or bracket. This dialdisk has a circular series of perforations 22", into which may be sprungthe inner end of a headed plunger or pin 23, mounted on a loose arm 23,which-is carried by the end of the shaft and which constitutes aknock-off arm by which the shipper'is released when the projecting hookend 23*, of said arm comes in engagement with the inwardly turned hook41 of the-vertical trip rod 40,

Verse rotation of the shafta20 by its torsion spring 21. It will beseenthat this stop pin determines the initial position of the dial plate ordisk 22, and also of the knock-off arm-23, which can be set to anycircumferential adjustment thereof by means ofthe latch 23. Obviouslythe nearerthe knock-off arm 23 is setto the stop pin 22 the larger willbe the arc of rotation permitted-it before it comes into engagement withthe hook at the lowerend of the trip rod 40, and consequently the longerwill be the duration of operation of the centrifugal.

The timer shaft 20 is'rotated against the t'ension of its torsion spring21 by means of the worm 19 and a worm-gear 18 the latter being fast onthe shaft-20. Such rotation, i

matic'sprayer I employ a'cam 24, adjustably' secured to the shaft 20 bymeans of an attachihg bolt 24 which passes through a countersunk arcuateslot 22 in the dial-plate, and through any one of an arcuate series ofbolt holes 2 1 in the cam, whereby the cam may be set to any desiredcircumferential adjustment with relation to the initial stop pin 22*, orin relation to the adjustable knock-off arm 23*.

This cam, after a short period of rotation which may be varied by theadjustment above described, engages an anti-friction roller 25 mountedon a tang 25*, carried in the end of the starting arm 37 of the sprayermechanism,

, This tang 5* is set at an angle of approximately 45 so as to resistthethrust of the is induced by the torsion spring 21 on the. shaft 20.

The details of the sprayer mechanism need not be particularly describedherein since it forms no part of this invention and is in reality animprovement upon that shown in United States Patent 1,224,095, April 24,1917 which, in its improved form, forms the subject matter of myco-pending application, now issued as Patent No. 1,585,608, dated May18,1926.

For present purposes it will suiiice to state that the fulcral end ofthe arm 37 is secured to a sleeve 32 surrounding the vertical shaft fromwhich both the timer and the sprayer are actuated in proper sequence.

The lower end of this sleeve carries a lateral arm 32, which engages ananti-friction roller 32 on a rocking angle lever 33, which is connectedwith the stem of the valve 33, which is raised to admit water to theoscillating spray-arm 33 which delivers the spray to the sugar. Theoscillatory sprayarm is actuated by a lever-33, and combined with it isa cam-roller 33 arranged to be engaged by a cam 34 in the-bottom of thesprayer casing. .A tension spring 33 acts to reversely rotate therock-arm 33 to close the valve when the rock-arm is re leased. The lowerarm of the angle lever 33 carries a stop pin 33 which serves, when thelever is 1n valve-closing position, to support the spray-actuating arm33 out of engagement with the cam 34, while allowing said I connected toa vertical adjusting screw 33 swung into engagement with a timer gear 35carrying a knock-off pin 35 which, after a predetermined arc ofrotation, engages a suitably arranged dog or stop-latch 36 to allow thetension spring 33 whose upper end is carried in a lateral extension ofthe lever 33 and which normally exerts a downward pull on said lever toshut off the-liquid'and reversely rotate the sleeve 32 to idle position.

It will be understood that any suitable construction of automaticallytimed spraying .mechanism may be used if so related to the centrifugaltiming mechanism, previously described, as to be started in operationthere- 'by after the centrifugal has been running for the properpredetermined period oftime. The operation of the device essentially isas follows. By, means of the hand-wheel 8,

c5? rotated in a clockwise direction from the idle position shown inFigure 1, the operator throws in the clutch 3 to operatively connect thedrive-shaft 1 with the loose pulley 2, and the centrifugal shaft pulleya so that the machine is started in operation. By the same movement,through the medium ofthe lever 11, and the brake-connecting rod 50, thebrake-shoes are contracted or released from engagement with the interiorof the pulley a;

At the same time, by means of the connecting trip-rod 15, the three-armlever 16 is rotated in a counter-clockwise direction, allowing theweight-arm 13 to drop into stop position to prevent ,return of the lever11 to idle position. This same movement of the three-arm lever 16 acts,through the clutch-lever 17, to operatively engage the clutch member 18,splined to the shaft 20 to its convenient driving clutch member 18which, in the form shown, is driven from the centrifugal spindle itselfby the connecting mechanism, shown in Figure 1 and F igure 6, so that ata single operation the centrifugal is started, the brake is released,the shipper-shaft is locked in operative position and the timermechanism, which determines the duration of the centrifugal machine op-'eration, is started in motion.

After the timer mechanism has rotated the shaft 20 and the adjustablearm 23, through a predetermined arc, the cam 24, by its engagement withthe cam roller 25, throws over the starting lever 37 of the sprayer andstarts the spraying operation which continues for a predetermined lengthof time, according to the setting of the sprayer'mechanismr Closelyfollowingthe-completing of the spraying operation the knock-off arm 23engages the hooked connecting link 40, and

'by pulling it down rotates the lever 16 in a clockwise direction,raising the weight-arm 13 out of locking position and allowing theshipper shaft 9 to rotate in a counter-clockwise direction under theaction of the torsion spring 6, thereby disconnecting the'clutch 3 fromthe driving pulley 2 and, at the same time, setting the brake-shoesagainst theinterior of the pulley a to stop the machine. This samemovement of the lever 16 disconnects the clutch 18 of the timer from thetimer driving train so that all the mechanism comes to rest and themachine is ready to discharge its load and to receive another, after'which the cycle of movements previ-' usly described is repeated.

It will be observed that the entire cen-' trifugal mechanism, includingthe sprayer,

requires no attention at all from the operator after he has thrownover-the hand-wheel 8 to actuate the shipper-shaft. He is then free togo on to other machines and give them similar treatment, while thecomplete cycle of operations is automatically continued after a machineis once started by-him.

The adjustments of the timer mechanism permit any desired variation inthe duration of the entire cycle of centrifugal operation or in theperiodof operation preceding the 5 starting of the sprayer or in theperiod of operation following the cessation of the spraying operation.

The arrangement, therefore, permits the expert foreman of thecentrifugal room to m accurately fix the duration or period of eachoperation of the machine and leaves the operation of the machineentirelyindependent of the judgment of the individual attendant whotakes care of it. This is an important 5 feature because the individualworkmen are veryv commonly not expert enough to properly gauge theduration of the variousoperations,and in consequence of this it oftenhappens that there is excessive waste by wash- .ing or insufficientpurging of the sugar before the'spraying operation. In this way eachoperation of the centrifugal mechanism is standardized so as to rendertheapparatus fool-proof against "costly mistakes by the operator. i

It will be noted in Figure 5 that in order to take up back-lash a shorttension spring 17, connected with an arm of the lever '17, and with afixed point of the frame is employed so that there is no danger, throughlooseness of the connections, that the clutch" 18 will he accidentallyreleased during the operation of the machine.

, What I claim is:

1. In a centrifugal apparatus,- the combination with a centrifugalmachine and its driving means, of means for starting the centrifugalthrough its driving connection, a brake and an automatically timedsprayer 4o cooperatively associated with the centrifugal,

and coordinated timing means acting to start the operation of thesprayer at a predetermined interval after the centrifugal is started andto apply the brake at a predetermined in '45 terval after the sprayingoperation has ceased.

2. The combination with a centrifugal machine and'its driving mechanism,of a manually operated starting element movable against yieldingresistance to establish operative connection between the centrifugal andits driving mechanism, an automatictiming "controller operativelyassociated with the "centrifugal, and acting, after a predetermined butvariable interval, to release the startingelement from operativeposition,

i thereby causing the stopping of the centrifugal,and a spra erinterconnected with the controller to'be s arted thereby at apredetermined intervalafter the starting of the centrifugal andto'bestopped aftera further interval independently of thefurther-movement of the starting element. a

3. The combination with a centrifugal sus- 6 5 pension shaft, of drivingand braking means associated therewith to operate thereon in alternationto each other, a rotary timer oper- 'atively combined with thecentrifugal and operating after apredetermined but variable period ofrotation from starting position, according to its adjustment, tocause'the cessation' of the driving action and the setting of the brake,and means operating in coordination with the driving and braking meansto restore the timer to said starting position after the timer hascompleted its operation.

5. In a centrifugal apparatus, the combination with a suspendedcentrifugal and its starting and stopping means including a selfsettingbrake, a sprayer, adjustable timing means cooperatively associated withthe.

sprayer and with the brake to control the starting and stopping of thesprayer and also the setting of the brake at predetermined but 'variableintervals in the operation of the cen-' trifugal.

6. In a centr1fugalapparatus, the combination with a centrifugal and itsdriving and braking means, a shipper for starting the centrifugal andreleasing the brake, a rotary timer, a timer-clutch actuated byconnections.

with the shipper, means adjustably secured to the timer shaft to releasesaid timer-clutch and simultaneously producea reverse drive releasingand brake-setting movement of the shipper to stop the centrifugal andthe timer aftefri'; a predetermined rotation of the timersha 7. In acentrifugal apparatus, the combination with a rotary centrifugal, atimershaft a sprayer, means for driving said timer an said sprayer fromthe centrifugal by independntly releasable connections, a ship iermechanism for starting and automatica ly "stopping'the centrifugal,saidsprayer and said shipper being operatively combined with the timerin order to automatically control the duration of the centrifugaloperation and of the spraying operation. 6

' 8. In a centrifugal apparatus, thecombination with a clutch-drivencentrifugal, a

timer device driven by a releasable clutch connection with thecentrifugal, shipper V mechanism having separate connections with the}centrifugal driving-clutch, and with the timer driving-clutchby whichthe centrifugal and thetimerl are started 'in operation,

a brake for the centrifugal also controlled by said shipper, said timerhaving connections for releasing both clutch-mechanisms and set,-

ting the centrifugal brake after a predetermined period, the timerdevicebeing adjustable to lengthen or shorten the duration of thecentrifugal operation.

9. In a centrifugal apparatus the combination with shipper mechanism forstarting and automatically stopping the centrifugal, and adjustabletiming mechanism actin to stop the centrifugal after a predeterminedperiod of operation, a self-stoppin sprayer device, sprayer startingmeans a justably connected with the timer to start the sprayerautomatically after any desired predeter mined eriod of operation ofthecentrifugal.

10. centrifugal apparatus for purity ing sugar or the like embracing incombination with a centrifugal machine its driving means'and acoordinated self-setting brake, normally controlled means for startingthe centrifugal and releasing the brake, a sprayer, means whereby thesprayer is started in action at a predetermined but variable intervalafter starting the centrifugal and is stopped after a predeterminedperiod of spraying, means for discontinuing the action of the drivingmeans and applying the brake at a redetermined interval following thestopplng of the sprayer.

In witness whereof, I have subscribed the above specification.

EUGENE ROBERTS.

